Sabatini



Dec. 17, 1929. w. SABATINI 1,739,523

DEVICE FOR WORKING OUT CALCULATIONS IN CONNECTION WITH STRUCTURES OF REENFORCED CONCRETE Filed Dec. 16, 1925 3 Sheets-Sheet 1 Dec. 17, 1929. w. SABATINI 1,739,523

DEVICE FOR WORKING OUT CALCULATIONS IN CONNECTION WITH STRUCTURES OF REENFOROED CONCRETE Filed Dec. 16, 1925 5 Sheets-Sheet 2 Patented Dec. 17, 1929 WASHINGTON SAB ATINI, F ONEGLIAfITALY DEVICES FQR WORKIN G OUT GALCTJ'L'Ai'lIIONS, IN CONNECTION WITH STRUCTURES OF.

REENFORCED CONCRETE Application filed December 16,1925, Serial This invention relates to a machine for calculations in connectionwith constructional problems-in reenforced concrete based upon the mechanical application :of formulae referring toycalculationsfor reenforced concrete laid downin a hand book composed bythe present applicant and published by the Editor Ulrico Hoepliof Milan. These formulae are reduced to the, simplest possible expression and represent. the fundamental conception for the construction of, theprjesent. device for calculations in connection with reenforced concrete. 1 1 l These formulae expressthe dimensions. of

1 thecono-rete and of the iron as well for floors and'their girders and tanks as afunction of only one or of two variables.

The machine accordingtothe present in vention essentially consists of two, cylinders to which is imparted a reciprocating and a .rotaryimotion by means of two buttons of which each one is rotatably arrangedin the centre of a discsupplied with two groups of concentrically arranged. holes. v The inner holes of thelefthand disk correspond with the dimensions of; floors and of tanks, the outer holes with those of girders. The inner holes of the right hand disc correspond with the weights ofthe floors and with the height oftl e tanks, the outer holes with the weights of the girders. Each button carriesv two keys mounted upon a radially movable arm one key of which is. adapted to be. engaged "With .theainner' holes While the. other key engages with the outer holes of the disc.

It therefore resultsthat with each position of the two thumb buttons therecorresponds one point only upon. the. surfaceof each cylinder; upon the cylinders are indicated the required solutions and by a perfect correspondence between the rotary sand reciprocating motion of the cylinders and the rotary v motions of the buttons, any point of its surface can be brought in front of two suitable reading slots through which the solutions can be read. One cylinder has marked thereon the solution of the floors and of the tanks as a function of two variables and the heights of the girders as a function of only one variable. The other cylinder has indicated No ..75,844, and in Italy January 13, 1925.

thereon the solutions ofthe dimensions of non of the girders, as a function of two variables. Reference will now be made to the accompanyin g drawings, in which Figure 1 is a top plan view of the device;

Figure 2 is a top plan view of the device .with the cover removed;

Figures 7 and 8 show tables adapted to be i applied upon the two cylinders.

In these figures inwhich like numbers indicate like or similar parts, the device, enclosed in a rectangular box comprises two metallic discs fastened ontlie cover arranged side by side of which the disc 11 at the left carries two concentric groups of holes, the inner 201 of which corresponds with the dimensions of the floors and of the tanks and the outer one corresponds with dimensions of the girders. In the centre of thisdisc there is rotatably supported a button 2 carrying a rotatable arm which is provided with two keys 4c, an outer and an inner key either of which the movement ofthe arm cam be brought into engagement with the outer or inner group of holes respectively. The button 2 of the left hand disc is fastened upon the vertical shaft 5 and its rotation is imparted bythe helical wheel 6 simultaneously to two helical wheels 7, 7 p which transmit to the cylinders 8', 8, alike rotary motion in 0 pos'ite directions. y

The. metallic disc 1 at the right-hand side is also provided with; two groups of concentrio holes orwhich "the inner roup 22 cor responds with the weights ofthefloors: and

with the height of the tanks and the outer group" 23 corresponds with the weights of the fgirders. The button 2 ofthis disc carries alsoa means arm which arm is preview with two keys 4', an outer and an inner key which, by the movement of the arm, can be engaged with the outer or inner group of holes respectively. The button 2 of the right-hand disc is fastened on the vertical shaft 9 which carries at its lower end a toothed wheel 10 in engagement with the two racks 11, 11 which are connected with the cylinders 8, 8 so as to impart to them a reciprocating opposite motion when one button is rotated and without preventing the rotation of the cylinders when driven by the rotation of the other button.

The cylinders 8, 8 have tables on their peripheral surfaces as shown in Figures 7 and 8. These tables represent in the case of the lower cylinder thicknesses of concrete for floors and tanks, sections of iron for floors and tanks, and heights of girders while the table on the upper cylinder represents sections of iron for girders.

The cylinders 8, 8 with their tables marked thereon are adapted to pass respectively behind reading slots 12' and 13, which slots are uncovered by openings in discs 17 and 18 controlled respectively by buttons 12 and 13. An arrow 19 is marked on each disc so that by rotating for example the disc 17 operated by the button 12 and in bringing the arrow in a direction towards the right, towards the bottom and towards the left in the reading slot 12, there will be read respectively the height of the girder, the thickness of the floor and the section of the iron of the floor.

Similarly the button 13 operates the disc 18 and in bringing its arrow 19 upwardly in the reading slot 1.3, there will be uncovered a number which indicates the total section of iron of the girder.

The numbers of the tables carried by the cylinders 8, 8 which appear in the reading slots 12, 13 show a point at the left or right or below the number. This renders it possible to simplify the table as each point indi- 5 cates a decimal and constitutes a conventional means adopted by the inventor. For instance .19 indicates 19.25; 1. 1 indicates 14.5 and 4. indicates 4.7 5.

The point to the left of the number, indicates 0.25, the point below the number 0.5 and the point to the right 0.75 which decimal fractions will have to be added to the number.

Two examples will now be given relating to calculations for a floor, and a girder To calculate for example, a floor of 3 meters span with a load of 200 kilo per square meter.

The button 2 is rotated to the point of the inner row of holes which corresponds with 3111; then the button 2 at the right isrotated to the point at the inner row of holes which corresponds with the load 200 kilo. Then the button 12 is rotated in a position in which 'the arrow 19 is directed towards the bottom and in the reading slot 12 is read a that is 4 square centimeter, which represents the section of the iron requested for a meter width of the floor. Then the button 12 is rotated in a position so that the arrow 19 on it is directed towards the right and in the reading slot is read 11, that is, 11.75 square centimeter which is the total thickness of the floor.

To calculate for example a girder with a span of 5 meters and which has to carry a total load of 3000 kilo (weight of floor and load).

The button 2 at the left is rotated and brought over the number 5 of the outer group of holes indicating the span of the girder and the button 2 at the right is brought over the number of the outer group of holes which indicate the load of 3000 kilo; then the button 18 is rotated so that the arrow 19 is directed against the left and in the reading slot 13 will appear the number 8 which indicates the section in iron in square centimeter.

In order to establish the height of the girder the button to the left is unaltered and the button to the right brought upon the letter T which is a constant of the machine.

Then the button 12 will be rotated so that its arrow 19 will be directed towards the left. In this position of the button 12 its disc uncovers in the sight slot 12 the number 20 that is 20 centimeter of height of the girder.

It is evident that the device can also serve for the solution of similar problems, in which as in the calculation of a floor or of a girder the result can be expressed by simple formulee with one or two variables.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is A calculating device of the character described, including in combination a pair of cylinders marked with the required solutions, buttons, a rotatable arm associated with each button, gearing interposed between the buttons and cylinders for imparting a rotary motion and a reciprocating movement alternately to said cylinders so as to rotate or reciprocate them with equal speed in opposite directions, and graduated discs each provided with two groups of concentric holes serving as setting points for the adjacent rotatable arm of each button and said holes correspond ing to points on the cylinders which represent the required solution In testimony whereof I have signed my name to this specification.

WASHINGTON SABATINI. 

